The invention relates to a method for cutting structural components to be joined by laser radiation, guided by means of a computer-controlled manipulation system that has preset a nominal path for each structure structural component, wherein the nominal path corresponds to a joining line that is curved as a result of at least one especially three-dimensionally shaped structural component.
DE-Z TechPress 1/97, pp. 21 through 26, discloses a method for cutting structural components to be joined by means of laser radiation, wherein a cutting head of a laser cutting device emitting laser radiation is guided by means of an automated manipulation system. Guiding is carried out along a predetermined nominal path.
When cutting is carried out in order to produce structural components to be joined, the nominal path must correspond as precisely as possible to the joining line. When the structural components are to be joined at curved joining lines, for example, by means of welding with high-energy radiation, such as laser radiation, the manipulation system during cutting of each one of the structural components to be joined must effect a path of the laser radiation which corresponds as precisely as possible to the curved joining line. A plurality of error sources can impair the precision. The shaping of the structural components to be joined and the path precision of the manipulation system should be mentioned as examples. Moreover, the method should provide a production output as high as possible so that high cutting and welding speeds are desired. The quality of the welding connection, however, should not suffer so that the cutting gap width and the welding seam width must be maintained within predetermined limits. For the aforementioned reasons, it is required to cut the structural components to be joined as precisely as possible.
DE 38 18 402 C1 discloses a method for torch cutting where the penetration line of two bodies is measured based on their actual dimensions. For this purpose, a predetermined area is assigned to both bodies, respectively, which area comprises the penetration line. Measured values of both areas are saved and, based on these values, the penetration line is calculated according to which the welding seam is then produced. The use of a computer-controlled manipulation system in interaction with a laser beam is not disclosed. During cutting no correction whatsoever of the torch cutting machine is carried.
U.S. Pat. No. 5,463,202 describes a method for processing workpieces by laser radiation wherein secondary light originating at the work location is determined and supplied to a control device that loads an NC device provided for controlling a worktable supporting the workpiece. Guiding of the laser radiation by means of a computer-controlled manipulation system is not carried out.